package com.show.itmuch.contentcenter.configuration;

import com.alibaba.nacos.api.exception.NacosException;
import com.alibaba.nacos.api.naming.NamingService;
import com.alibaba.nacos.api.naming.pojo.Instance;
import com.netflix.client.config.IClientConfig;
import com.netflix.loadbalancer.AbstractLoadBalancerRule;
import com.netflix.loadbalancer.BaseLoadBalancer;
import com.netflix.loadbalancer.Server;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.alibaba.nacos.NacosDiscoveryProperties;
import org.springframework.cloud.alibaba.nacos.ribbon.NacosServer;

@Slf4j
public class NacosWeightedRule extends AbstractLoadBalancerRule {

  @Autowired private NacosDiscoveryProperties nacosDiscoveryProperties;

  @Override
  public void initWithNiwsConfig(IClientConfig clientConfig) {
    // 读取配置文件，并初始化 NacosWeightedRule，该方法一般为空
  }

  @Override
  public Server choose(Object key) {

    try {
      BaseLoadBalancer loadBalancer = (BaseLoadBalancer) this.getLoadBalancer();
      log.info("lb = {}", loadBalancer);
      // 想要请求的微服务的名称
      String name = loadBalancer.getName();
      // 实现负载均衡算法。。
      // 拿到服务发现的相关API
      NamingService namingService = nacosDiscoveryProperties.namingServiceInstance();
      // nacos client自动通过基于权重的负载均衡算法，给我们选择一个实例。
      Instance instance = namingService.selectOneHealthyInstance(name);
      log.info("选择的实例是：port = {}, instance = {}", instance.getPort(), instance);
      return new NacosServer(instance);
    } catch (NacosException e) {
      return null;
    }
  }
}
// Spirng Cloud Commons --> 定义了标准
// Spring Cloud loadbalancer --> 没有权重
